The present invention relates to an article conveying device, and more particularly to such a conveying device having a moving carriage and a buffer storage.
In the handling of mail it is necessary that each item be individually canceled and this process requires that the items be correctly oriented. Since large post offices must handle hundreds of thousands of letters per day, the canceling machinery must have an extremely high throughput rate, but the rate is significantly reduced if the machine must be frequently stopped to remove jammed or nonlevel, that is, skewed, items. Canceling machines generally are designed to operate at a constant rate, therefore, it is necessary that they be supplied with a uniform rate of input items. However, the feeder machinery that transfers the bulk mail into the canceler generally does not work at a uniform rate but at a rate that varies over short time periods. Therefore, there is a need for a device to interface mail feeding machinery with canceling machines to level the skewed mail, generate an output of single, nonoverlapping items, and provide a uniform output rate despite variations in the rate of input.
A stacking device directed to the above problem is that shown in U.S. Pat. No. 3,690,474 issued to Klappenecker. This device forms a buffer stack of articles which are transported over a moving carriage fed by a conveyor belt. This device, however, does not provide any means for leveling skewed mail.
Additional article handling devices are shown in U.S. Pat. No. 3,193,280 to Gutierrez, 3,511,368 to Kajitani and 3,347,348 to Flint et al.